#include <pthread.h>
#include <signal.h>
//#include <linux/tcp.h>
#include <netinet/tcp.h>
#include "net.h"

void cli_data_handle (void *arg);
void setKeepAlive (int sockfd, int attr_on, socklen_t idle_time, socklen_t interval, socklen_t cnt);

void sig_child_handle (int signo)
{
	if (SIGCHLD == signo) {
		waitpid (-1, NULL, WNOHANG);
	}
}

int main (void)
{

	int fd = -1;
	struct sockaddr_in sin;

	signal (SIGCHLD, sig_child_handle);

	/* 1. 创建socket fd */
	if ((fd = socket (AF_INET, SOCK_STREAM, 0)) < 0) {
		perror ("socket");
		exit (1);
	}

	/*允许绑定地址快速重用 */
	int b_reuse = 1;
	setsockopt (fd, SOL_SOCKET, SO_REUSEADDR, &b_reuse, sizeof (int));

#if 0
	/* 允许广播 */
	int b_br = 1;
	setsockopt (fd, SOL_SOCKET, SO_BROADCAST, &b_br, sizeof (int));

	/* 设置接收超时 */
	struct timeval tout;
	tout.tv_sec = 5;
	tout.tv_usec = 0;
	setsockopt (fd, SOL_SOCKET, SO_RCVTIMEO, &tout, sizeof (struct timeval));

#endif


	/*2. 绑定 */
	/*2.1 填充struct sockaddr_in结构体变量 */
	bzero (&sin, sizeof (sin));
	sin.sin_family = AF_INET;
	sin.sin_port = htons (SERV_PORT);	//网络字节序的端口号

	/*优化1: 让服务器程序能绑定在任意的IP上 */
#if 1
	sin.sin_addr.s_addr = htonl (INADDR_ANY);
#else
	if (inet_pton (AF_INET, SERV_IP_ADDR, (void *) &sin.sin_addr) != 1) {
		perror ("inet_pton");
		exit (1);
	}
#endif
	/*2.2 绑定 */
	if (bind (fd, (struct sockaddr *) &sin, sizeof (sin)) < 0) {
		perror ("bind");
		exit (1);
	}

	/*3. 调用listen()把主动套接字变成被动套接字 */
	if (listen (fd, BACKLOG) < 0) {
		perror ("listen");
		exit (1);
	}
	printf ("Server starting....OK!\n");
	int newfd = -1;
	/*4. 阻塞等待客户端连接请求 */

	struct sockaddr_in cin;
	socklen_t addrlen = sizeof (cin);
	while (1) {
		pid_t pid = -1;
		if ((newfd = accept (fd, (struct sockaddr *) &cin, &addrlen)) < 0) {
			perror ("accept");
			break;
		}

		/*创建一个子进程用于处理已建立连接的客户的交互数据 */
		if ((pid = fork ()) < 0) {
			perror ("fork");
			break;
		}

		if (0 == pid) {			//子进程中
			close (fd);
			char ipv4_addr[16];

			if (!inet_ntop (AF_INET, (void *) &cin.sin_addr, ipv4_addr, sizeof (cin))) {
				perror ("inet_ntop");
				exit (1);
			}

			printf ("Clinet(%s:%d) is connected!\n", ipv4_addr, ntohs (cin.sin_port));
			cli_data_handle (&newfd);
			return 0;

		} else {				//实际上此处 pid >0, 父进程中 
			close (newfd);
		}


	}


	close (fd);
	return 0;
}

void cli_data_handle (void *arg)
{
	int newfd = *(int *) arg;

	printf ("Child handling process: newfd =%d\n", newfd);

	int keepAlive = 1;			//设定KeepAlive
	int keepIdle = 5;			//开始首次KeepAlive探测前的TCP空闭时间
	int keepInterval = 5;		//两次KeepAlive探测间的时间间隔
	int keepCount = 3;			//判定断开前的KeepAlive探测次数

	setKeepAlive (newfd, keepAlive, keepIdle, keepInterval, keepCount);


	//..和newfd进行数据读写
	int ret = -1;
	char buf[BUFSIZ];
	char resp_buf[BUFSIZ + 10];
	while (1) {
		bzero (buf, BUFSIZ);
		do {
			ret = read (newfd, buf, BUFSIZ - 1);
		} while (ret < 0 && EINTR == errno);
		if (ret < 0) {

			perror ("read");
			exit (1);
		}
		if (!ret) {				//对方已经关闭
			break;
		}
		printf ("Receive data: %s\n", buf);

		if (!strncasecmp (buf, QUIT_STR, strlen (QUIT_STR))) {	//用户输入了quit字符
			printf ("Client(fd=%d) is exiting!\n", newfd);
			break;
		}

		bzero (resp_buf, BUFSIZ + 10);

		strncpy (resp_buf, SERV_RESP_STR, strlen (SERV_RESP_STR));
		strcat (resp_buf, buf);
		do {
			ret = write (newfd, resp_buf, strlen (resp_buf));
		} while (ret < 0 && EINTR == errno);

	}
	close (newfd);

}

void setKeepAlive (int sockfd, int attr_on, socklen_t idle_time, socklen_t interval, socklen_t cnt)
{

	setsockopt (sockfd, SOL_SOCKET, SO_KEEPALIVE, (const char *) &attr_on, sizeof (attr_on));
	setsockopt (sockfd, SOL_TCP, TCP_KEEPIDLE, (const char *) &idle_time, sizeof (idle_time));
	setsockopt (sockfd, SOL_TCP, TCP_KEEPINTVL, (const char *) &interval, sizeof (interval));
	setsockopt (sockfd, SOL_TCP, TCP_KEEPCNT, (const char *) &cnt, sizeof (cnt));
}
